1. Field of the Invention
The present invention relates to an emergency call service system in an IP network and a method thereof, and more particularly, to an emergency call service system in an IP network, which is configured to provide an emergency call service in an IP network, and a method thereof.
This work Was supported by the IT R&D program of MIC/IITA[2005-S-097-02, Development of BcN Integrated Network Control and QoS/TE Management Technology]
2. Description of the Related Art
To provide an emergency call service in the Internet Protocol (IP) network, a position of a user needs to be detected, and the quality of service (QoS) between the user and an emergency center must be ensured.
When a user terminal having an IP address requests an emergency call connection to an emergency center in the IP network, a call agent (CA) must ensure a connection to the nearest emergency center from a position of a calling party especially because the calling party is in an emergency situation.
For example, an IP multimedia subsystem (IMS) terminal automatically registers its position to a base station, so that the call agent can connect the terminal to the nearest emergency center with reference to the registered position information. However, a non-IMS terminal does not support this automatic registration function, and thus the call agent cannot detect a position of the non-IMS terminal, thereby failing to make an emergency call connect between the terminal and the emergency center.
FIG. 1 illustrates a configuration of a conventional emergency call service system in an IP network.
The conventional emergency call service system includes a user terminal 111, first and second concentrators 112 and 113, access and edge routers 114 and 115, and an emergency center 116 in each of areas 110. The emergency call service system further includes call agents (CA) 150 connected to the respective edge routers 115 of the areas 110.
The user terminal 111 is an IMS terminal having an IP address. The user terminal 111 registers its position information to a base station (not shown), and then provides a user with services such as a Voice over Internet Protocol (VoIP) and a Multimedia over IP (MmoIP), and an emergency call service.
The first and second concentrators 112 and 113 each is implemented as a digital subscriber line access multiplexer (DSLAM). The first and second concentrators 112 and 113 multiplex signals received from a plurality of user terminals 111, and transmit to a high-speed backbone circuit.
The access router 114 performs routing between the second concentrator 113 and the edge router 115, and transmits a signal of the second concentrator 113 to the edge router 115. The edge router 115 transmits the signal transmitted from the access router 114 to the call agent 150 or another communication party in another network.
The emergency center 116 performs an emergency call connection to the user terminal 111 under control of the call agent 150, and provides a user with required services.
The call agent 200 is connected to a plurality of user terminals 111. When a specific user terminal 111 requests a service, the call agent 200 detects a proper communication party and relays the service. Particularly, when the specific user terminal 111 sends an emergency call, the call agent 200 detects a position of the corresponding user terminal 111 by using a base station, and then connects an emergency call between the corresponding user terminal 111 and the nearest emergency center 116.
As described above, when the user terminal is the IMS terminal, the conventional emergency call service system can provide an emergency call service by determining a position of the user terminal through the base station. However, in the case of the non-IMS terminal, the emergency call service cannot be provided at all because of the absence of a terminal-position detection unit.